In the 18th century, David Hume wrote that “no truth appears to me more evident than that beasts are endow’d with thought and reason as well as men.” Yet animal cognition has remained a controversial subject in science ever since. In the first of two episodes, Christian and Joe discuss the work of Dutch-American primatologist Frans de Waal, and ask the question of not just whether animals are smarter than we understand, but why the evidence of animal cognition is often so difficult for we humans to grasp.